Apple's valuation is still so sky-high compared to so many other technology companies and almost all of it is based on ONE product (iPhone) in a product category that they didn't invent (smartphones) and were a relatively late entry. They are in essence a "one-hit-wonder". The risk going forward is way beyond that of Amazon, Microsoft, Google, and many others.....which is why AAPL trades at 9 P/E and is having a hard time keeping it above 9. Sure they have wildly successful products in iPod and iPad, but without iPhone the valuation will be cut in half or even further. iPhone is irreplaceable, yet very vulnerable at the present time.
The problem with comparing AAPL to AMZN is that AMZN doesn't have any real competitors, they focus strickly on growth, and when they want to start turning a profit they just have to stop spending everything on growth. Plus Bezo is still there. Jobs probably gets to much credit for AAPL, but perception is reality